1. Field of the Invention
The invention relates generally to a device for skin treatment and, more particularly, to a device for skin treatment, which is constructed such that a plurality of needles coated with an insulator is inserted into the skin and an electromagnetic wave is transmitted through the needles inserted into the skin.
2. Description of the Related Art
As seen in paper 1 (Hyun-Ju Jeong, The measurement of the thickness of the Korean's skin by ultrasound, KyungBuk Univ., 1990. Vol. 28(2), 121-129) and paper 2 (Jin-Sung Park, The measurement of the thickness of the Koreans' skin by a CT scan, Catholic Univ., 1995. Vol. 33, 303-311), the thickness of an Oriental's skin is generally about 1.5 mm to 4.0 mm, and the thickness of the outer layer of the skin is about 0.06 mm to 0.2 mm.
For example, in terms of the thickness of the skin, the cheek which has the thickest skin is about 2.7 mm (±0.40 mm), and the forehead and the eyelid which have the thinnest skin are about 0.84 mm.
A person's skin consists of an outer layer and an inner layer. The inner layer serves as the main support of the skin and is made up of a protein which is called collagen. The collagen has a triple helical structure including a fibroblst and a polypeptide. If the collagen tissue is heated, the protein matrix is physically changed at the shrinkage temperature. The remodeling of soft tissue is a physical change that occurs at the cellular or molecular level. The shrinkage or the partial denaturization of collagen generated by artificial heat decomposes the bonding of a triple helix, thus destroying the intermolecular bonding of the matrix. When it is compared with the shrinkage resulting from the movement of fibroblasts into a wound and natural healing power, the remodeling of soft tissue is an immediate process. When cells shrink, the collagen is situated at a lower position and acts as a static support matrix for the taut soft tissue. The initial deposition of a scar matrix and the subsequent remodeling provide means for changing the shape and consistency of soft tissue for beauty purposes.
Generally, in order to treat various scars or skin lesions or to improve the skin or wrinkles for the sake of beauty, a method of applying various energy sources to an associated portion and solidifying the tissue has been used. For example, methods of transferring thermal energy have been proposed.
According to the methods, various kinds of energy are applied to the target portions of the skin tissue to intentionally cause wounds, thus stimulating the collagen of the inner layer and inducing the regenerating action of the collagen, therefore regenerating skin tissue.
Referring to papers, it is reported that the denaturization of collagen occurs most reliably at a temperature from 65° C. to 75° C. However, the effects of treatment may vary according to how the patient endures the pain at this temperature.
Conventionally, a target portion of the skin is heated by radiating light, near infrared rays, and microwaves. According to the conventional methods, heat is applied to the outer layer of the skin to reach the target portion of the skin.
However, when thermal energy is transmitted from the outer portion of the skin to the target portion (the outer layer, inner layer, or subcutaneous fat) of skin tissue, the thermal energy is greatly scattered or absorbed. Thus, there is less energy to be substantially transmitted to the inner layer. If the thermal energy which is applied to the skin is increased to solve the problem, the outer layer is burned.
Further, a method of using physical energy has been proposed. According to the method, a superfine needle is inserted into a target portion of the skin tissue to physically stimulate it. However, the method is problematic in that a user personally inserts the needle into the skin, so that it is difficult to precisely control the depth to which the needle is inserted into the target portion of skin tissue. When this method is used, the skin is damaged only physically and not damaged thermally, so that the effect of regenerating collagen or damaged skin is restricted. Further, if the needle is inserted at an angle to the outer layer of the skin, an incident angle differs from an emergent angle, so that a wound may undesirably result and the inner layer of the skin may be stimulated.
Further, when a roller equipped with a plurality of needles is rubbed against the skin, an incident angle differs from an emergent angle, thus causing an undesirable wound and pain.
Further, the important parameters of a conductive needle which transmits electromagnetic waves to the skin include the angle of the conductive needle when it is inserted into the skin and the diameter of the conductive needle. Since pain and a burn are caused when the conductive needle is inserted into the skin, there is a need for the development of a conductive needle which is optimized to eliminate the pain and burning. However, the conventional conductive needle is manufactured indiscriminately without taking into consideration the angle and diameter of the conductive needle. Therefore, it is difficult to eliminate the pain and burning.
A conventional device having a needle unit is problematic in that needles to which high-frequency waves are applied are inserted directly by a user using his or her hand, so that the depth of insertion, the strength, a balanced state during insertion, and the time it takes to perform the insertion are not constant. Consequently, the conventional device varies in treatment effect, pain, and operation time, so that it is difficult to standardize the treatment effect, pain, and operation time.
In order to accomplish the purpose of a desired treatment, a plurality of needles must be almost simultaneously inserted into the body, and electric energy must be applied to ends of the needles. When the plurality of needles is inserted into a very shallow layer of the skin, the depth of the end of each needle must be precisely controlled according to a predetermined value.
When the plurality of needles is not controlled horizontally as shown in FIG. 1, the surface of the skin may be undesirably damaged. Therefore, a method of controlling the plurality of needles horizontally is required.
Further, in the case of inserting the device into the human body, it must always be inserted into the skin using regular pressure so as to lessen the sensation of fear and pain of a patient.
FIG. 2 is a graph illustrating survey results regarding the fear and pain felt when medical treatment is performed on people receiving clinical treatment using irregular pressure. The graph shows that people receiving clinical treatment suffer more fear and pain under irregular pressure in comparison with regular pressure.
The needles inserted into the skin must always be dislodged from the skin within a predetermined period of time so as to remove the danger of an accident and lessen the pain.
If the needles are dislodged from the skin at a different time for each shot during the medical treatment, the skin may be scratched by the needles or high-frequency waves may be directly applied to the outer layer of the skin while one portion of the skin has been treated and then the needles are moved, so that the skin may be undesirably damaged as shown in FIG. 3. Further, if the needles stay in the skin for a lengthy period of time, a patient's pain increases.
FIG. 4 is a graph showing survey results for people receiving clinical treatment. As shown in the drawing, as time for inserting the needles into the skin increases, the number of people receiving clinical treatment who feel pain increases.
The conventional device is problematic in that it is impossible to know the replacement time even if the needles are no longer being used.
As shown in FIGS. 5 to 7, when a predetermined period of time has passed or the needles have been used for a predetermined number times, the ends of the needles are undesirably burnt or bent. Thus, when a predetermined period of time has passed or the needles have been used for a predetermined number times, it is necessary to prevent the use of the needles for safety's sake. Further, in the case of simultaneously using a bipolar type needle and a monopolar type needle, a user must control the amount of energy or know whether opposite pole plates are installed or not. Thus, means for storing and displaying these pieces of information is required.
The method and object of treatment depend on the using amount or characteristics of the needles. Thus, a sensing device is required to read pieces of information of the needles and control the parameters of the equipment.
If the needles are inserted into the skin to a depth of 0.2 mm or more and high-frequency energy is applied, a very small amount of protein denaturation occurs. The denatured protein sticks to the needles, so that the needles are not easily removed from the skin.
If the needles slide horizontally with not being removed from the skin, the skin is damaged by the needles as shown in FIG. 3.
Further, when the plurality of needles is inserted into the skin, the longer the time taken to insert the needles into the skin is, the greater a patient's fear and pain are. Thus, it is required to reduce the time taken to insert as much as possible. Further, when the needles are inserted using the hand, fine vibrations are generated rightward and leftward. A treatment which is not standardized increases the patient's fear and pain. FIG. 8 is a diagram showing patients' pain as a function of the speed and method used to insert the needles.
A pushing force of an electric-powered device such as a solenoid valve is weaker than a recovery force, so that a means for supplementing the recovery force and aiding in removing the needles from the skin is required. Therefore, it is required to reduce the time it takes to separate the needles from the skin for safety's sake, thus reducing the stress of an operator and a patient.